Such gas injectors are used for example in combination with other fuel injectors, such as petrol injectors, with it being possible for a driver to switch for example between operating with gas and operating with the other fuel. In such vehicles this allows the fuel costs to be considerably reduced as running a petrol-driven vehicle currently costs an end consumer twice as much as a vehicle driven by a combination of gas, for example natural gas, and petrol.
In gas injectors of the type of prior art, the valve needle and the valve seat of a valve are manufactured from a material pairing metal/metal. This however has the drawback of not allowing such good sealing of the valve.
Alternatively, instead of the material pairing metal/metal, metal/nonmetal may now be used to form the valve. The nonmetal used for the valve seat in this case is an elastomer, for example hard rubber. The valve pin itself is still made of metal. Forming the valve seat from rubber has the advantage of allowing better sealing of the valve and/or injector than when, as in the prior art, the valve seat is manufactured from a metal. The pairing metal/rubber does however have the drawback that in cold ambient conditions, for example even at just below 0° C., a “sticking” or “seizing” of the valve needle in the rubber valve seat may occur. In these conditions therefore, in order to compensate this drawback the gas injector has to be heated. Without such a valve heating function the gas injectors having a valve seat made of rubber are incapable of operating at temperatures below zero, this leading to an unacceptable disadvantage for customers.